Compliant guiding catheter sheath system

ABSTRACT

A guiding catheter system employs a compliant shaft with an inflatable balloon affixed to a distal portion of the shaft. The inflatable balloon includes channels that allow some amount of blood to flow past the balloon when inflated in a blood vessel. One or more inflation lumens is in fluid contact with the balloon and allows inflating the balloon from a proximal end of the catheter. A series of perfusion orifices may be included on the shaft proximal to the balloon.

FIELD OF THE INVENTION

[0001] The invention relates generally to guiding catheter systems, and,more particularly, to guiding catheters for accessing the coronary sinusand other heart vessels.

BACKGROUND OF THE INVENTION

[0002] Guiding catheters are instruments that allow a physician tolocate and cannulate vessels in a patient's heart for performing variousmedical procedures, including venography and implanting of cardiacpacing devices. Cannulating heart vessels requires navigating a smalldiameter, flexible guide through convoluted vasculature into a heartchamber, and then into a destination heart vessel. Once the destinationheart vessel is reached, the catheter acts as a conduit for insertion ofpayloads into the vessel.

[0003] Once the vessel has been cannulated by a guiding catheter, anocclusion device may be utilized to hold the distal end of the guidingcatheter in place during various procedures. The occlusion device blocksblood flow through the vessel at the same time lodging the catheter inplace.

[0004] However, the blood flow cannot be blocked indefinitely, asocclusion of blood flow may cause detrimental effects on the patient.Therefore the clinician must be concerned about leaving the occludingdevice in place for too long. There is a need in the art for an improvedguiding catheter for accessing heart vessels that can be guided througha convoluted pathway and lodged for a longer period of time in a bloodvessel. The present disclosure discusses these and other needs in theart.

SUMMARY OF THE INVENTION

[0005] The present invention discloses a guiding catheter that canprovide access to venous structures for medical procedures and be firmlylodged in those vessels while still allowing some amount of blood flowin the vessels.

[0006] In one embodiment, a guiding catheter for use with a guideapparatus for cannulating a blood vessel includes a flexible shafthaving an open lumen. The open lumen is placeable over the guideapparatus so that the flexible shaft substantially assumes the shape ofthe guide apparatus. The guiding catheter includes a balloon at a distalportion of the flexible shaft. The balloon includes one or more externalchannels. An inflation lumen is disposed along the flexible shaft and influid connection with the balloon. Pressurization of a fluid in theinflation lumen inflates the balloon. The inflated balloon is arrangedto lodge in the blood vessel and permit an external fluid flow throughthe external channels.

[0007] In one arrangement, the guiding catheter further includes one ormore perfusion orifices of the flexible shaft proximal to the balloon.The perfusion orifices are in fluid connection with the external fluidflow and the open lumen of the flexible shaft. The balloon may beconfigured to include a plurality of expansion lumens, the externalchannels defined between adjacent expansion lumens. In somearrangements, the balloon may include three or four expansion lumens.The three expansion lumen arrangement may be configured to define anapproximately triangular cross sectional shape.

[0008] The external channels of the balloon may be orientedsubstantially parallel to a centerline of the flexible shaft. In anotherarrangement, the external channels include a helical channel extendingfrom a distal end of the balloon to a proximal end of the balloon.

[0009] In another embodiment of the present invention, a method ofcannulating a destination vessel involves introducing a guide apparatusinto the destination vessel. A guiding catheter is placed over the guideapparatus so that a distal portion of the guiding catheter is disposedin the destination vessel. A balloon disposed on a distal portion of theguiding catheter may be inflated so that the distal portion of theguiding catheter is lodged in the destination vessel and an externalflow is permitted through an external channel of the balloon.

[0010] Introducing the guide apparatus in the destination vessel mayinvolve actuating a steering mechanism of the guide apparatus to directa distal end of the guide apparatus. In another arrangement, introducingthe guide apparatus in the destination vessel involves manipulating apre-shaped distal portion of the guide apparatus to direct a distal endof the guide apparatus.

[0011] The above summary of the present invention is not intended todescribe each embodiment or every implementation of the presentinvention. Advantages and attainments, together with a more completeunderstanding of the invention, will become apparent and appreciated byreferring to the following detailed description and claims taken inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 is a cutaway view of a heart, showing a guiding catheteraccording to embodiments of the present invention deployed in the rightatrium;

[0013]FIG. 2 is a side view of a distal end of the catheter according toembodiments of the present invention;

[0014]FIG. 3 is a cross sectional view of the catheter and balloon ofFIG. 2, corresponding to section 2-2 of FIG. 2;

[0015]FIG. 4 is a cross sectional view of the catheter shaftcorresponding to section 2-2 of FIG. 2 showing an alternate crosssectional shape of the balloon;

[0016]FIG. 5 is a side view of a distal end of a catheter illustrating ahelical channel arrangement according to embodiments of the presentinvention; and

[0017]FIG. 6 is a cross sectional view of the catheter showing perfusionorifices according to embodiments of the present invention.

[0018] While the invention is amenable to various modifications andalternative forms, specifics thereof have been shown by way of examplein the drawings and will be described in detail herein. It is to beunderstood, however, that the intention is not to limit the invention tothe particular embodiments described. On the contrary, the invention isintended to cover all modifications, equivalents, and alternativesfalling within the scope of the invention as defined by the appendedclaims.

DETAILED DESCRIPTION OF VARIOUS EMBODIMENTS

[0019] In the following description of the illustrated embodiments,references are made to the accompanying drawings which form a parthereof, and in which is shown by way of illustration, variousembodiments in which the invention may be practiced. It is to beunderstood that other embodiments may be utilized, and structural andfunctional changes may be made without departing from the scope of thepresent invention.

[0020] In broad and general terms, a guiding catheter according toembodiments of the present invention employs a flexible shaft having aballoon attached at a distal end. The balloon has channels that allowfluid to flow past the inflated balloon. The guiding catheter includesan open lumen in the flexible shaft adapted for the introduction ofpayloads through the catheter system. The guiding catheter can be placedover a smaller maneuverable guiding apparatus that is used to locate avessel. In one application, the guiding catheter can be used tointroduce a payload into the coronary sinus or other heart vessels.

[0021] Turning now to FIG. 1, a guiding catheter, generally indicated byreference numeral 100, is shown deployed in the right atrium 101 of theheart. The guiding catheter 100 includes a flexible shaft 102 with anopen lumen, and an inflatable balloon 104 at a distal end of the shaft102. A distal tip 106 of the catheter 100 is positioned in the coronarysinus 108. The balloon 104 can be inflated to lodge the flexible shaft102 in the coronary sinus 108.

[0022] The balloon 104 contains channels 112 that allow an external flowof blood to move past the lodged catheter shaft 102. In general, theterm “external flow” as used herein generally refers to a flow past theouter surfaces of the catheter shaft 102 and the balloon 104. Byproviding a bypass external blood flow, the balloon 104 canadvantageously remain inflated in place for longer periods of time. Oncethe balloon 104 is lodged into place, the flexible catheter shaft 102can act as a guide for other devices such as contrast media, implantableleads, and diagnostic devices.

[0023] Implantation procedures may vary depending on the goal of theprocedure and the condition of the patient. For purposes of example, oneprocedure for implanting a pacing lead into the coronary sinus 108 willbe described in relation to FIG. 1. A maneuverable guide apparatus 122may first be guided into the right atrium 101 to locate the ostium 124of the coronary sinus 108. The guide apparatus 122 may be any type ofpre-shaped and/or steerable apparatus. For purposes of illustration, theguide apparatus 122 will be described as a pre-shaped, steerableelectrophysiology (EP) catheter.

[0024] During the EP catheterization procedure, a clinician inserts theEP catheter 122 into an access vessel 126 through an incision orintroducer sheath puncture 128. The access vessel 126 may include any ofthe large veins of the upper limb system such as the cephalic orsubclavian veins. Lower limb vessels such as the femoral artery are alsoused as access points for many heart cannulation procedures.

[0025] Once the EP catheter 122 is in the right atrium, the shape and/orsteering apparatus of the EP catheter 122 may be used to assist inlocating the coronary sinus ostium 124. The EP catheter 122 may alsocontain distal electrodes (not shown) that assist in locating the ostium124. Signals from the electrodes can be used to “map” electricalactivity of the heart tissues. Once the clinician has found the coronarysinus ostium 124, the guiding catheter 100 may be slid over the EPcatheter 122 to introduce the guiding catheter 100 into the coronarysinus 108.

[0026] In an alternate approach to placing the guiding catheter 100 inthe coronary sinus 108, the guiding catheter 100 may be first introducedinto the access vessel 126 and into the right atrium 101. After thedistal tip 106 of the guiding catheter 100 is located in the rightatrium 101, the EP catheter 122 can be placed into the open lumen of theguiding catheter 100 so that the EP catheter 122 emerges into the rightatrium 101. The guiding features of the EP catheter 122 can then be usedto locate the coronary sinus ostium 124, after which the guidingcatheter 100 can be slid over the EP catheter 122 into the coronarysinus 108.

[0027] The flexible shaft 102 of the guiding catheter 100 is typicallymade relatively compliant so that the shaft 102 can be placed over aguide apparatus without substantially disturbing the shape of theapparatus. This compliant shaft 102 also helps reduce anatomical traumaduring placement procedures. Once the guiding catheter 100 is fullyseated in position, the balloon 104 can be inflated to hold the flexibleshaft 102 in place. The inflated balloon 104 provides the catheter 100with an anchor point to prevent dislodgment of the shaft 102 duringfurther procedures.

[0028] Once the guiding catheter 100 is lodged into place, the EPcatheter 122 can be removed. The guiding catheter 100 remains as aconduit for payloads directed to the heart. In one example, a contrastmedia can be injected into the flexible shaft 102 for fluoroscopicmapping of coronary vessels. It is appreciated that the channels 112 ofthe inflated balloon 104 may allow some small amount of the contrastmedia to flow out of the coronary sinus 108. However, the contrast mediahas significantly greater viscosity than blood, therefore this“backflow” of contrast media will be minimized.

[0029] After performing fluoroscopy, a device such as a pacing lead maybe implanted into a branch vessel of the coronary sinus 108. In oneprocedure, the pacing lead is inserted into the guiding catheter 100until in emerges into the coronary sinus 108. A stylet or guidewire maybe used to assist placing the pacing lead in the branch vessel. Afinishing wire or other fixing device can be inserted to hold the pacinglead into place, after which the balloon 104 can be deflated and theflexible shaft 102 of the catheter 100 withdrawn. The shaft 102 mayinclude peel away features such as a longitudinal pre-stress on theshaft walls that allow the shaft 102 to be peeled apart as it iswithdrawn. Finally, after withdrawing the shaft 102, the finishing wireor fixing device is removed to complete the procedure.

[0030] Turning now to FIG. 2, construction details of the guidingcatheter 100 are illustrated. The shaft 102 is typically an elongatedtubular member having an open guide lumen 202. The guide lumen 202 isformed to allow the shaft 102 to be introduced over guide apparatus aswell as acting as a conduit for payloads introduced into the catheter100.

[0031] The balloon 104 is fixably mounted at a distal portion of theshaft 102. The balloon 104 is in fluid contact with one or moreinflation lumens 204 used to inflate and deflate the balloon 104. Theinflation lumens 204 may be formed on an inside or outside surface ofthe flexible shaft, or the inflation lumens 204 may be formed within thewalls of the flexible shaft 102. The inflation lumens 204 are accessiblefrom the proximal end of the catheter 100, thereby allowing theclinician to inflate and deflate the balloon 104 using a proximal devicesuch as a syringe.

[0032] The balloon 104 contains channels 112 that allow blood flow tobypass the inflated balloon 104. In FIG. 2, these channels 112 areoriented approximately parallel to the centerline of the shaft 102. Thisorientation of the channels 112 is typical, since it also corresponds tothe direction of blood flow in the blood vessel. However, otherorientations of the channels 112 may be used, assuming the channels 112allow blood to flow past the inflated balloon 104.

[0033] The balloon 104 may be fabricated with any suitable crosssectional shape. Two exemplary cross sectional shapes are shown in FIGS.3 and 4. In FIG. 3, the balloon 104 includes a substantially triangularcross sectional shape. The balloon 104 includes three expansion lumens302 that expand to lodge against the walls of a blood vessel. Thechannels 112 are defined by the spaces between the expansion lumens 302.The balloon 104 may be bonded or otherwise affixed to the shaft 102 atportions of the balloon 104 that define the channels 112. The expansionlumens 302 may be in fluid connection with each other and the inflationlumens so that all expansion lumens 302 inflate simultaneously.Alternatively, each lumen 302 may have an associated inflation lumen sothat each expansion lumen 302 is independently inflatable.

[0034] The flexible shaft 102 as illustrated in FIG. 3 may include aninner liner 304 and an outer sheath 306. The inner liner 304 may beformed of a lubricious material such as polytetrafluoroethylene (PTFE).The outer sheath 306 may be fabricated of a smooth, wear resistantpolymer material. The distal tip 106 of the shaft (see FIG. 2) mayinclude a soft covering to prevent tissue trauma when introducing thecatheter 100 into blood vessels. The flexible shaft 102 may includeother features such as a stainless steel braiding (not shown) embeddedwithin the shaft walls to improve lateral and torsional stiffness.

[0035] In some configurations, the flexible shaft 102 is made withoutsignificant stiffening features such as a braid. A relatively compliantflexible shaft 102 can be made to more easily slide over an EP catheteror other guide apparatus. A compliant shaft 102 is less likely to“overpower” the shape of a guide apparatus in such a situation and isless likely to induce tissue trauma along the guide path. Finally, acompliant shaft 102 is more easily withdrawn and easier to peel awayshould a pre-stress feature be included in the shaft walls.

[0036] Because the catheter 100 can be introduced over a guideapparatus, the flexible shaft 102 can be made without any pre-shapedcurve or variable flexibility along the shaft's length. This allows thecatheter 100 to be fabricated for general-purpose use. In general, thecatheter 100 can be used with any guide apparatus that will fit withinthe guide lumen 202 of the catheter 100.

[0037] Turning now to FIG. 4, a four-lobed balloon 104 is illustrated.As with the triangular shape of FIG. 3, the portions of the balloonsdefining the channels 112 may be bonded or otherwise fixed to the shaft102. The four expansion lumens 302 may be in fluid connection with eachother or independently inflatable.

[0038] Although the channels 112 may be oriented substantially parallelto the centerline of the flexible shaft 102, other channel orientationsmay be possible. For example, FIG. 5 shows a helical channel 112extending along the balloon 104. Such a helical channel 112 may providethe balloon 104 with a more secure contact surface when the balloon 104is inflated in a blood vessel.

[0039] Additional features may be included with a catheter 100 accordingto embodiments of the present invention to increase the amount of bypassblood flow. For example, FIG. 6 shows a cross sectional view of a distalportion of the catheter's flexible shaft 102. A series of perfusionorifices 602 are included on a portion of the shaft walls proximate theballoon 104. The perfusion orifices 602 are in fluid connection with theguide lumen 202 and an external flow outside the flexible shaft 102.

[0040] Blood can enter the guide lumen 202 through the distal tip 106 ofthe flexible shaft 102 and can exit through the orifices 602 asindicated by the bold arrows. Blood can also flow in a directionopposite that indicated by the arrows. The effectiveness of theperfusion orifices 602 may depend on the size of any payload deployedwithin the catheter 100, as large payloads may block the guide lumen 202to some extent. It is appreciated that the combination of bypassfeatures of the balloon 104 and the perfusion orifices 602 may provideenhanced bypass blood flow in many applications.

[0041] From the description provided herein, those skilled in the artare readily able to construct and use a guiding catheter according toembodiments of the present invention. It will, of course, be understoodthat various modifications and additions can be made to the preferredembodiments discussed hereinabove without departing from the scope ofthe present invention. Accordingly, the scope of the present inventionshould not be limited by the particular embodiments described above, butshould be defined only by the claims set forth below and equivalentsthereof.

What is claimed is:
 1. A guiding catheter for use with a guide apparatusfor cannulating a blood vessel, comprising: a flexible shaft having anopen lumen, the open lumen placeable over the guide apparatus so thatthe flexible shaft substantially assumes the shape of the guideapparatus; a balloon at a distal portion of the flexible shaft, theballoon including one or more external channels; and an inflation lumendisposed along the flexible shaft and in fluid connection with theballoon, pressurization of a fluid in the inflation lumen inflating theballoon, the inflated balloon arranged to lodge in the blood vessel andpermit an external fluid flow through the external channels.
 2. Theguiding catheter of claim 1, wherein the flexible shaft comprises one ormore perfusion orifices proximal to the balloon and in fluid connectionwith the external fluid flow and the open lumen of the flexible shaft.3. The guiding catheter of claim 1, wherein the balloon comprises aplurality of expansion lumens, the external channels defined betweenadjacent expansion lumens.
 4. The guiding catheter of claim 3, whereinthe plurality of expansion lumens comprises three expansion lumens. 5.The guiding catheter of claim 3, wherein the plurality of expansionlumens define an approximately triangular cross sectional shape.
 6. Theguiding catheter of claim 3, wherein the plurality of expansion lumenscomprise four expansion lumens.
 7. The guiding catheter of claim 1,wherein the external channels are oriented substantially parallel to acenterline of the flexible shaft.
 8. The guiding catheter of claim 1,wherein the external channels comprise a helical channel extending froma distal end of the balloon to a proximal end of the balloon.
 9. Aguiding catheter system for cannulating a blood vessel, comprising: aguiding catheter comprising: a flexible shaft having an open lumen; aballoon at a distal portion of the flexible shaft, the balloon includingone or more external channels; and an inflation lumen disposed along theflexible shaft and in fluid connection with the balloon, pressurizationof a fluid in the inflation lumen inflating the balloon, the inflatedballoon arranged to lodge in the blood vessel and to permit an externalfluid flow through the external channels; and a maneuverable guideapparatus placeable within the open lumen of the guiding catheter sothat the flexible shaft substantially assumes the shape of the guideapparatus.
 10. The guiding catheter system of claim 9, wherein theflexible shaft comprises one or more perfusion orifices proximal to theballoon and in fluid connection with the external fluid flow and theopen lumen of the flexible shaft.
 11. The guiding catheter system ofclaim 9, wherein the balloon comprises a plurality of expansion lumens,the external channels defined between adjacent expansion lumens.
 12. Theguiding catheter system of claim 11, wherein the plurality of expansionlumens comprises three expansion lumens.
 13. The guiding catheter systemof claim 11, wherein the plurality of expansion lumens define anapproximately triangular cross sectional shape.
 14. The guiding cathetersystem of claim 11, wherein the plurality of expansion lumens comprisefour expansion lumens.
 15. The guiding catheter system of claim 9,wherein the external channels are oriented substantially parallel to acenterline of the flexible shaft.
 16. The guiding catheter system ofclaim 9, wherein the external channels comprise a helical channelextending from a distal end of the balloon to a proximal end of theballoon.
 17. The guiding catheter system of claim 9, wherein themaneuverable guide apparatus comprises a pre-shaped catheter.
 18. Theguiding catheter system of claim 9, wherein the maneuverable guideapparatus comprises a steerable catheter.
 19. The guiding cathetersystem of claim 9, wherein the maneuverable guide apparatus comprises anelectrophysiology catheter.
 20. A method of cannulating a destinationvessel, comprising: introducing a guide apparatus into the destinationvessel; placing a guiding catheter over the guide apparatus so that adistal portion of the guiding catheter is disposed in the destinationvessel; and inflating a balloon disposed on a distal portion of theguiding catheter so that the distal portion of the guiding catheter islodged in the destination vessel and an external flow is permittedthrough an external channel of the balloon.
 21. The method of claim 20,wherein introducing the guide apparatus in the destination vesselcomprises actuating a steering mechanism of the guide apparatus todirect a distal end of the guide apparatus.
 22. The method of claim 20,wherein introducing the guide apparatus in the destination vesselcomprises manipulating a pre-shaped distal portion of the guideapparatus to direct a distal end of the guide apparatus.